转番茄GGPS2基因烟草的构建及弱光耐受性分析

Construction of transgenic tobacco expressing tomato GGPS2 gene and analysis of its low light tolerance

摘要:

为探讨弱光处理对转番茄 Solanum lycopersicon L. GGPS2基因烟草的类胡萝卜素、叶绿素合成及耐弱光性的影响，将SlaGGPS2基因和绿色荧光蛋白报告基因 (GFP) 经农杆菌介导转入烟草 Nicotiana tabacum L. cv. Wisconsin 38。PCR检测证明抗卡那霉素烟草含有nptII、SlaGGPS2基因，且无农杆菌污染；荧光检测发现，抗卡那霉素烟草的根尖呈现特有的荧光，由此说明获得了整合SlaGGPS2和GFP等外源基因的转基因烟草。弱光处理后，发现转SlaGGPS2基因烟草的类胡萝卜素含量、叶绿素总量、光合速率、单位叶面积重、总干重、根冠干重比均比野生烟草高，达到了差异显著水平。证实SlaGGPS2基因增加了弱光下烟草的类胡萝卜素含量、叶绿素总量，增强了光合速率，促进了生物量积累及其向根部的分配，提高了烟草弱光下的耐受性，推测可用于其他作物的耐弱光性改良。

Abstract:

To explore the influence of low light on the synthesis of carotenoids, chlorophyll and the adaptability of transgenic plants with tomato Solanum lycopersicon L. GGPS2 gene, we constructed a vector containing a GGPS2 gene with green fluorescent protein (GFP) as report gene under the control of a cauliflower mosaic virus 35S promoter and introduced it into tobacco Nicotiana tabacum L. cv. Wisconsin 38 by Agrobacterium tumefaciens-mediated transformation. PCR analysis of the DNA from kanamycin resistant tobacco indicated that the transgenic tobacco containing the nptII gene, SlaGGPS2 gene and without contamination of Agrobacterium. We also detected the root tip of kanamycin resistant tobacco showing characteristic fluorescence. The contents of carotenoid, chlorophyll and photosynthesis of transgenic tobacco increased in comparison with wild tobacco after low light treatment. In addition, leaf mass per unit area, total dry weight, ratio of root to shoot in transgenic tobacco were all higher than that of the wild tobacco, which proved that the transgenic tobacco could increase the accumulation of biomass and promote it transport to root. The transgenic tobacco with SlaGGPS2 gene can increase the contents of carotenoid, chlorophyll, enhance the photosynthetic rate, promote the biomass accumulation and its distribution to root. Hence, the transgenic tobacco with SlaGGPS2 gene had increased low light tolerance and the SlaGGPS2 gene maybe can be used in other crops.